Correlations among total colonoscopic findings, clinical symptoms, and laboratory markers in ulcerative colitis

Colonoscopy plays an integral role in the diagnosis, management and surveillance of ulcerative colitis (UC). In the present study we assessed the relationship between endoscopic and histological findings, clinical symptoms, and laboratory data. We performed total colonoscopy examinations in 54 consecutive patients with UC. Seven segments (appendiceal region, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum) were scored for endoscopic and histological activity. The patients were also evaluated using a symptom-activity index and laboratory markers: C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell (WBC) and platelet (plt) counts. There was a significant positive correlation between endoscopic and histological scores (r(s) = 0.738), and between symptom activity score, endoscopic score (r(s) = 0.444), and histological score (r(s) = 0.557). Although the endoscopic and histological scores of distal colonic lesions (rectum-sigmoid, endoscopic: r(s) = 0.515, histological: r(s) = 0.624) correlated with clinical symptoms, there was no similar correlation for the proximal colon (appendiceal region-descending; endoscopic, r(s) = 0.268, histological, r(s) = 0.329). CRP, ESR, and WBC count also correlated with the sum of endoscopic and histological scores (CRP, r(s) = 0.447, r(s) = 0.369; ESR, r(s) = 0.483, r(s) = 0.589; WBC, r(s) = 0.338, r(s) = 0.330), whereas platelet count did not (r(s) = 0.171, r(s) = 0.210). In partciular, CRP and ESR were well correlated with the activity of proximal colonic lesions (CRP, r(s) = 0.474, r(s) = 0.480; ESR, r(s) = 0.423, r(s) = 0.529) rather than with that of distal lesions (CRP, r(s) = 0.236, r(s) = 0.212; ESR, r(s) = 0.368, r(s) = 0.497). In this study, clinical symptoms reflected the activity of distal colonic lesions, whereas CRP and ESR reflected the activity of proximal lesions. Therefore, total colonoscopy may be indicated when CRP or ESR is elevated in UC patients in clinical remission.